Electrical earth borehole logging is well known and various devices and various techniques have been described for this purpose. Broadly speaking, there are two categories of electrical logging apparatus. In the first category, that of galvanic type, one or more source/receiver electrodes are used in conjunction with a return electrode, which might be a logging tool's body or mandrel. In a second category, that of inductive measuring tools, an antenna within the measuring instrument induces electrical field within the earth formation, resulting in a signal response at either the same or a separate receiver antenna. In both cases the measured responses are affected by properties of the earth formation including electrical conductivity, magnetic permeability, and dielectric permittivity and thus, affected by the pore volume or porosity of the rock matrix, and water saturation.
Parameters of the formation, such as, for example, resistivity or dielectric constant, may be estimated by transmitting an electromagnetic (EM) wave into the formation, and receiving EM response at one or more receivers (e.g., at receiver antennas). The attenuation and phase shift between spaced receivers may be determined and used to estimate the complex dielectric constant of the formation.